If your business texts customers in the US from a normal phone number, 10DLC decides whether those texts arrive. This is a plain-English explanation of what 10DLC and A2P 10DLC registration are, why unregistered texts are now blocked, what "10DLC compliance" means day to day, and how it relates to call trust settings like SHAKEN/STIR.
1. What is 10DLC?
10DLC stands for "10-digit long code": an ordinary US phone number with an area code, like (512) 555-0123. Businesses use these numbers for texting because customers recognise them as local and can text back.
A2P means "application-to-person": messages sent by software (a CRM, booking system or marketing tool) rather than a person typing on a phone. Missed-call text-backs, appointment reminders and review requests from GoHighLevel are all A2P messages.
So A2P 10DLC is business software texting from local numbers, and the US carriers (T-Mobile, AT&T, Verizon and others) require it to be registered.
2. What is 10DLC registration?
10DLC registration is how a business tells the carriers who it is and what it sends. It goes through The Campaign Registry (TCR), usually via your texting platform (in GoHighLevel, the Trust Center / A2P wizard). You register two things:
- A Brand: your legal business: name, EIN (tax ID), address, website and contact details, exactly as on official records.
- A Campaign: what you send and why: the use case (for example customer care or appointment reminders), sample messages, how people opt in, and how they opt out.
Then your phone numbers are linked to the approved campaign.
There are a few brand types:
| Type | Who it's for | Trade-off |
|---|---|---|
| Sole proprietor | Individuals or very small businesses without an EIN | Lowest limits; typically one campaign and one number |
| Low-volume standard | Businesses with an EIN sending modest daily volumes | Cheaper, with lower throughput |
| Standard | Businesses that need higher volumes | Can go through extra vetting for higher sending limits |
Fees are set by the registry and carriers and change over time, so check the current amounts in your platform before you submit. The step-by-step process in GoHighLevel is in the 10DLC registration guide.
3. Why it matters now: unregistered texts are blocked
Since February 1, 2025, the major US carriers block all text messages sent from unregistered 10DLC numbers. This isn't occasional filtering any more: if your number isn't linked to an approved campaign, your texts simply don't arrive, and you may not get an obvious error.
That's why businesses suddenly find their reminders and missed-call text-backs "stopped working". If that sounds familiar, check registration first, then the workflow troubleshooting guide.
4. What is 10DLC compliance?
Registration gets you approved; A2P 10DLC compliance keeps you approved. Carriers keep checking what you actually send. Staying compliant means:
- Clear opt-in: people agree to receive texts, with an unticked consent box on forms that says what they'll get and that message and data rates may apply.
- Easy opt-out: STOP works on every number, and you never text someone who opted out.
- HELP replies with your business name and contact details.
- Send only what you registered. A campaign approved for appointment reminders shouldn't be used for promotions; that may need its own campaign.
- Matching website pages: a privacy policy that says mobile numbers won't be shared or sold for marketing, and SMS terms covering frequency, costs, STOP and HELP.
- Sensible sending: respect quiet hours, avoid link shorteners from public services, and don't send content carriers restrict (for example cannabis, loans or third-party lead generation).
Breaking these rules can get messages filtered, a campaign suspended, or numbers blocked. If your campaign was rejected, see why A2P campaigns get rejected and how to fix them.
5. Does 10DLC apply to me?
- Texting US numbers from a US local number through software? Yes.
- Toll-free numbers use a separate toll-free verification instead.
- Short codes (5–6 digits) have their own approval process.
- UK, EU and Australia don't use 10DLC, but have their own rules: GDPR and PECR in the UK and EU, and the Spam Act and Sender ID Register in Australia.
- Agencies register each client sub-account's own brand. See A2P 10DLC for GoHighLevel agencies.
6. 10DLC vs SHAKEN/STIR: texts vs calls
People often mix these up. 10DLC is about texts. For calls, GoHighLevel's Trust Center has separate settings that help your calls get answered instead of being labelled "Spam Likely":
- SHAKEN/STIR: verifies that your outgoing calls really come from you. Registering includes a friendly name for your business.
- CNAM: the caller name some phones show.
- Voice Integrity: registers your numbers' use case and call volume with carriers to protect their reputation.
If you text and call customers, set up both. This matters even more if you use outbound Voice AI calls.
7. Quick 10DLC checklist
- Business details match official records exactly (legal name, EIN, address).
- A live website on your domain with a privacy policy and SMS terms.
- Forms with an optional, unticked SMS consent checkbox.
- A use case and sample messages that match what you'll really send.
- STOP and HELP tested on every number.
- Numbers linked to the approved campaign.
- Call trust (SHAKEN/STIR, CNAM, Voice Integrity) set up if you call customers.
Want 10DLC handled for you?
I'm Arslan Mumtaz, a software engineer who registers A2P 10DLC brands and campaigns in GoHighLevel, fixes rejected campaigns and sets up the compliance pages carriers check. A2P registration is $99, and agencies can hand over every sub-account through a monthly VA plan.